IJSM/5349/5.4.2016/MPS Training & Testing Aerobic Fitness and Technical Efficiency at High Intensity Discriminate between Elite and Subelite Tennis Players Authors E. Baiget1, X. Iglesias2, F. A. Rodríguez2 Affiliations 1 Universitat de Vic – Universitat Central de Catalunya, Sport Performance Research Group, Vic, Spain 2 Universitat de Barcelona, Institut Nacional d’Educació Física de Catalunya, INEFC-Barcelona Research Group on Sport Sciences, Barcelona, Spain ˙ Key words Abstract were compared. INT showed greater VO2max, VO2 ●▶ endurance tennis test − 1 − 1 ▼ at VT2 (ml · kg · min ), test duration (s), final ●▶ technical effectiveness The aim of this study was to determine whether stage (no.), hits per test (no.) and TE ( % of suc- ●▶ maximum oxygen uptake selected physiological, performance and techni- cessful hits), as compared with NAT (p < 0.05). At ●▶ international tennis players cal parameters derived from an on-court test are high exercise intensity (stages 5 and 6), the INT capable of discriminating between tennis players achieved better TE than NAT (p = 0.001–0.004), of national and international levels. 38 elite and and the discriminant analyses showed that these subelite tennis players were divided into interna- technical parameters were the most discrimi- tional level (INT, n = 8) and national level players nating factors. These results suggest that this (NAT, n = 30). They all performed a specific endur- specific endurance field test is capable of dis- ance field test, and selected physiological (maxi- criminating between tennis players at national ˙ mum oxygen uptake [VO2max], and ventilatory and international levels, and that the better aero- thresholds [VT1 and VT2]), performance (test bic condition of the INT is associated with better duration, final stage and hits per test) and techni- technical efficiency at higher exercise intensities. cal (technical effectiveness [TE]) parameters Introduction 25, 2015]. A previous study reported that, on ▼ average, players earned their first ATP point at Downloaded by: Cornell. Copyrighted material. High-level tennis players compete worldwide in 16.9 ± 1.2 years, and then took 4.5 ± 2.1 years to accepted after revision international tennis circuits governed by the transition to the top 100 at the age of 21.5 ± 2.6 February 15, 2016 Association of Tennis Professionals (ATP) and the years [27]. On the other hand, players at the International Tennis Federation (ITF). The ATP minor competitive level who have not yet man- Bibliography comprises 62 ATP World Tour tournaments (i. e., aged to obtain international classification (i. e., DOI http://dx.doi.org/ 10.1055/s-0042-104201 ATP World Tour Masters 1000, 500 and 250 ATP ranking) focus their competitive activity on Published online: 2016 events) in 31 countries, and about 150 ATP Chal- national category tournaments in their respec- Int J Sports Med lengers events. The ITF Men’s Circuit (Futures tive countries. © Georg Thieme tournaments) offers more than 600 tournaments A competition tennis match play includes inter- Verlag KG Stuttgart · New York across 77 countries and provides the entry level mittent short-term periods (1–9 s) of moderate ISSN 0172-4622 to professional tournaments enabling players to to maximum exercise intensity (i. e., strokes, eventually reach the ATP World Tour. The tourna- starts and stops, direction changes and short Correspondence ment structure is hierarchical and success is accelerations) interspersed by rest intervals of Dr. Ernest Baiget Universitat de Vic - Universitat measured by player rankings; this structure is short (maximum of 20 s between points) to Central de Catalunya organized in different competitive levels accord- medium duration (maximum of 90 s between Sport Performance Analysis ing to the prize money and ranking points offered change ends) [9, 25]. The physiological exercise Research Group [27]. According to the ITF, a player with ATP rank- intensities are typically moderate, ranging from Vic, Spain ing is an experienced professional world-class 70–90 % of HRmax and 50–60 % of maximum oxy- Sagrada Família ˙ player that competes internationally and whose gen uptake (VO2max), although during long rallies 7, Vic ˙ Spain 08500 major source of income is the tournaments prize- intensity may be higher (i. e., 80 % of VO2max and Tel.: + 34/938/816 164 money [ITF, International tennis number (ITN), close to 100 % of HRmax) [8]. In recent years, the Fax: + 34/938/891 063 2012. http://www.tennisplayandstay.com/itn/ physical demands upon elite tennis players has [email protected] about-the-itn/about-the-itn.aspx; accessed May increased significantly [3]. Although tennis con- Baiget E et al. Aerobic Fitness and Technical … Int J Sports Med Training & Testing IJSM/5349/5.4.2016/MPS tinues to be a technical/tactical game, nowadays 210 km · h − 1 Futures tournaments) with an ATP ranking (1 197 ± 330) and an serves are common and competitive performance depends International Tennis Number (ITN) of 1. The subjects in the sec- largely on the player’s physical ability [10]. Moreover, it has ond group (NAT, national level tennis players, n = 30) were recently been shown that playing consecutive prolonged tennis involved in regular tennis competition at the national level (i. e., matches implies reduction of match play performance (i. e., national tennis circuits) with an ITN ranging from 2 to 4 effective playing times), external load (i. e., 3D-movement load), (advanced), but without ATP ranking points. The subjects were and sprinting and jumping ability, as well as increased muscle recruited using a convenience sampling procedure among vol- damage markers and ratings of fatigue and soreness [14]. To unteers belonging to 4 high-level tennis academies and training reach the international level, tennis players also need to possess centres (see Acknowledgements). Sample size was calculated on ˙ specific physiological attributes such as aerobic fitness [9, 21], the basis of mean values ( ± SD) for relative V O2max obtained from muscle strength and power [26], and sport-specific technical a previous study [2] (63 and 56 ± 4.8 ml · kg − 1 · min − 1), which esti- skills as predominant factors (e. g., racket and ball handling skills mated that a minimum of 8 subjects per group was required and stroke skills, such as service abilities) [30]. (α = 0.05; β = 0.80; two-tailed). The unequal sample size was due In recent years, there has been growing interest in the assess- to the smaller population of players holding an ATP ranking. All ment of physiological and technical parameters using specific players were focused on tennis-specific training (i. e., technical field tests [2, 22, 24, 29, 31, 32]. Nowadays it is not possible to and tactical skills), aerobic and anaerobic training (i. e., on- and fully replicate in the laboratory the physiological demands, tech- off-court exercises), and resistance training. One participant in nical skills and muscle group involvement of tennis play, each group was left-handed. The study was performed in accord- although specific field tests allow to partly reproduce the com- ance with the ethical standards of the International Journal of plex demands of tennis [11]. Technical performance tests have Sports Medicine [17], and conformed to the recommendations been suggested to assess the players’ ability to aim the ball at a of the Declaration of Helsinki. All subjects voluntarily partici- given place on the court and the accuracy, speed and power of pated in the study after being informed about the scope and hits [22, 24, 31, 32], and incremental tests have been used to methods of the study, and delivered a written informed consent, assess specific endurance [2, 13, 15, 29]. On the other hand, a with parental permission when needed. The study was approved recently developed specific endurance field test (SET-Test) con- by the university institutional review board for studies involving ducted with a tennis ball machine allows physiological and tech- human subjects. nical parameters to be assessed simultaneously [2, 29]. Stemming from these tests, physiological (oxygen uptake [V ˙ O2], ventilatory Experimental design thresholds [VTs] or blood lactate) and technical (percentage of Participants performed an incremental tennis-specific endur- correct hits) variables have been described [2, 29], and their test- ance field test recently shown to be reliable and valid for the ˙ ing reliability and correlation with the competitive level estab- determination of VO2max and VTs [2]. Players were tested lished [2]. However, their discriminative ability between players between February and April in noncompetition weeks. All tests of different competitive levels has not been tested. were run in the morning (10–14 a.m.) of regular training days, Therefore, the aim of this study was to determine whether and performed on an outdoor tennis court (GreenSet surface, selected physiological, performance and technical parameters GreenSet Worldwide S.L., Barcelona, Spain), at an ambient tem- derived from a tennis-specific incremental field test are capable perature ranging from 18 to 23 °C, with stable environmental of discriminating between tennis players of different levels and wind conditions (i. e., air velocity < 2 m · s − 1, relative humi- (national vs. international level). dity 54.4–61.0 % [Kestrel 4000 Pocket Weather Tracker, Nielsen Downloaded by: Cornell. Copyrighted material. Kellerman, Boothwyn, PA, USA]). Measurements began after an 18-min standardized warm-up including: 10 min of jogging Methods around the court, dynamic flexibility, forward, sideways, and ▼ backwards running, and acceleration runs; 5 min of ground Participants strokes (players were asked to hit the balls to the centre of the 38 competitive male tennis players were divided into 2 groups court); and 3 min of test familiarization, performing the test pro- according to their level (● ▶ Table 1). The subjects in the first group tocol at the lowest work load (frequency of balls ejected from the − 1 (INT, international level tennis players, n = 8) were involved in ball machine [Ballf] = 9 shots · min ). To reduce interference regular tennis competition at the international level (i.